Extremely high pollution levels shrouded eastern China for the second time in about two weeks Tuesday, forcing airlines in Beijing and elsewhere to cancel flights because of poor visibility and prompting government warnings for residents to stay indoors.
The outlines of buildings in the capital receded into a white mist as pedestrians donned face masks to guard against the thick, caustic air, which stranded passengers during the first week of the country's peak, six-week period for travel surrounding the Chinese New Year on Feb. 10.
The U.S. Embassy reported a peak level of PM2.5 — one of the worst pollutants — at 526 micrograms per cubic meter, or "beyond index," and more than 20 times higher than World Health Organization safety levels over a 24-hour period.
Liu Peng, an employee at a financial institution in Beijing, said he will keep his newborn baby indoors.
"It's really bad for your health, obviously," Liu said. "I bike to work every day and always wear a mask. The pollution in recent years is probably due to the increase in private cars and government cars."
Beijing's official readings for PM2.5 were lower than the embassy's — 433 micrograms per cubic meter at one point in the afternoon— but even that level is considered "severe" and prompted the city government to advise residents to stay indoors as much as possible. The government said that because there was no wind, the smog probably would not dissipate quickly.
Visibility was less than 100 meters (100 yards) in some areas of eastern China, the official Xinhua News Agency reported. More than 100 flights were canceled in the eastern city of Zhengzhou, 33 in Beijing, 20 in Qindao and 13 in Jinan.
Every year, China's transport system bursts at the seams as tens of millions of people travel for the Lunar New Year holiday, in the world's largest seasonal migration of people.
Ren Haiqiang, a bank worker in his early 30s, said he had booked tickets to fly out of Beijing on Thursday to visit family in the coastal city of Dalian, but now worried about flight cancellations.
"Traveling over the holiday is already a huge hassle, along with all the gift-giving and family visits. We thought flying would be the best way to avoid the crush, but if the weather continues like this we'll be in real trouble," Ren said as he waited on line at a bakery in downtown Beijing.
Air pollution has long been a problem in Beijing, but the country has been more open about releasing statistics for some of the worst kinds of pollutants only since early last year. The city hit its highest readings since then two weeks ago, when U.S. Embassy readings of PM2.5 reached as high as 886 micrograms per cubic meter.
Celebrity real estate developer Pan Shiyi, who has previously pushed for cities to publish more detailed air quality data and who is a delegate to Beijing's legislature, called Tuesday for a "Clean Air Act." In less than three hours, his post was forwarded more than 2,300 times and received 14,184 votes, with 99 percent in favor.
AP reporter Christopher Bodeen and researcher Flora Ji contributed to this report.